1. Field
One or more embodiments described herein relate to a deposition apparatus.
2. Description of the Related Art
A variety of flat panel displays have been developed. Examples include a liquid crystal display (LCD) and an organic light emitting diode (OLED) display. An OLED display has improved luminance, viewing angle, and thinness compared with LCD displays. An OLED display is also self-emissive in that it does not require a backlight.
An OLED display may be fabricated using physical vapor deposition methods (e.g., vacuum deposition, ion plating, or sputtering methods) or chemical vapor deposition methods according to gas reaction. For example, the organic layer may be formed using a vacuum deposition method, which involves depositing an organic material on a substrate by evaporation in a vacuum. The organic material may be effusion cell sprayed onto the substrate. The effusion cell may include a crucible that receives an organic material and a heating element for heating the crucible.
In an attempt to form substrates of increased size and organic layers with good step coverage and uniformity, the effusion cell may be used to provide organic gaseous material. This material may be formed by evaporating organic material on the substrate held in a stationary state. The effusion cell may move in a vacuum chamber relative to the substrate. A guide rail may be installed to guide movement of the effusion cell, and the slide member may move along the guide rail.
Grease may be used to reduce friction between the guide rail and slide member. However, when the grease is heated during evaporation of the organic material and when the slide member moves, the evaporation gas may be contaminated in the chamber by the heated grease. The contaminated gas may reduce the lifespan of the OLED display. In addition, the requirement to resupply the grease causes delays and inefficiencies in the manufacturing process.